As a low-loss electrically conductive material, superconductor equipment such as cable, coil, motor, and magnet with the use of an oxide superconductor is developed. As a superconductor used for the superconductor equipment, an oxide superconductor such as an RE-123-based oxide superconductor (REBa2Cu3O7-x: RE being a rare-earth element containing Y, Gd etc.) is known. The RE-123 based oxide superconductor exhibits a superconductive property at around the liquid nitrogen temperatures and is capable of maintaining an excellent critical current density even in a strong magnetic field, and therefore is regarded as an extremely promising electrically conductive material in practice.
When applying the above-described oxide superconductor to electric equipment, the oxide superconductor processed into a wire is used as a conductor or a coil, in general. More specifically, an oxide superconductor wire can be obtained by forming an oxide superconductor layer on a metal substrate via an orientation layer having good crystal orientation, and laminating a protection layer and a metal stabilization layer so as to cover the oxide superconductor layer.
One of the issues for such an RE123-based oxide superconductor wire is that the rare earth-based oxide superconductor includes therein a material which is reactive with moisture. Thus, when using such an RE123-based oxide superconductor wire, it is important to consider a structure which is capable of preventing the oxide superconductor layer from deteriorating due to moisture. For example, a structure which is capable of preventing moisture from intruding from the terminal part of the oxide superconductor wire is required.
Conventionally, as a structure for sealing the connection part between the terminals of the oxide superconductor wires, a structure described in the following Patent Document 1 is known. In the structure described in Patent Document 1, the terminals of the tape-shaped superconductor wires of laminate structure are arranged so as to adjacent to each other, and a short-length superconductor wire for connection is provided which connects the wires so as to bridge therebetween. In this structure, the connection parts between the adjacent oxide superconductor wires and the short-length superconductor wire for connection are covered with an electrically conductive filler for sealing.